Simultaneous determination of cholesterol, ascorbic acid and uric acid as three essential biological compounds at a carbon paste electrode modified with copper oxide decorated reduced graphene oxide nanocomposite and ionic liquid

Analysis of food, pharmaceutical, and environmental compounds is an inevitable issue to evaluate quality of the compounds used in human life. Quality of drinking water, food products, and pharmaceutical compounds is directly associated with human health. Presence of forbidden additives in food products, toxic compounds in water samples and drugs with low quality lead to important problems for human health. Therefore, attention to analytical strategy for investigation of quality of food, pharmaceutical, and environmental compounds and monitoring presence of forbidden compounds in materials used by humans has increased in recent years. Analytical methods help to identify and quantify both permissible and unauthorized compounds present in the materials used in human daily life. Among analytical methods, electrochemical methods have been shown to have more advantages compared to other analytical methods due to their portability and low cost. Most of big companies have applied this type of analytical methods because of their fast and selective analysis. Due to simple operation and high diversity of electroanalytical sensors, these types of sensors are expected to be the future generation of analytical systems. Therefore, many scientists and researchers have focused on designing and fabrication of electroanalytical sensors with good selectivity and high sensitivity for different types of compounds such as drugs, food, and environmental pollutants. In this paper, we described the mechanism and different examples of DNA, enzymatic and electro-catalytic methods for electroanalytical determination of drug, food and environmental compounds.

Electrochemical Sensors, a Bright Future in the Fabrication of Portable Kits in Analytical Systems

This paper reports an electroanalytical sensor developed based on reduced graphene oxide/FeNi3 (FeNi3/rGO)-ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate (HMPF6) carbon paste electrode (CPE) for determining the antioxidant additive tertbutylhydroquinone (TBHQ) in the presence of folic acid. The FeNi3/rGO synthesized by hydrothermal strategy and characterized by X-ray diffraction (XRD) and FESEM methods. The electrochemical response were found to be linearly symmetrical to TBHQ and folic acid concentrations in the range from 0.05 to 900 μM and 0.6–1100 μM with detection limits of 10.0 nM and 0.1 μM, respectively. The FeNi3/rGO/HMPF6/CPE showed high-quality for determination of TBHQ in the presence of folic acid in the real samples with the separation potential ∼600 mV.

3D reduced graphene oxide/FeNi3-ionic liquid nanocomposite modified sensor; an electrical synergic effect for development of tert-butylhydroquinone and folic acid sensor

An amplified voltammetric sensor based on platinum nanoparticle/polyoxometalate/two-dimensional hexagonal boron nitride nanosheets composite and ionic liquid for determination of N-hydroxysuccinimide in water samples

This study suggests a carbon paste electrode modified with CuO nanoparticles and n-hexyl-3-methylimidazolium hexafluorophosphate (CPE/CuO-NPs/HMIPF6) as a powerful tool for the analysis of epinine for the first time. It has been confirmed that CPE/CuO-NPs/HMIPF6 can improve the sensitivity of epinine electro-oxidation and reduce the overvoltage of this drug compared to an unmodified electrode. The CuO nanoparticles are characterized by XRD and TEM methods. The CPE/CuO-NPs/HMIPF6 exhibited a detection limit of 0.2 μM and a dynamic range of 0.7–900 μM for analysis of epinine by the square wave voltammetric method. Epinine determination was performed successfully by CPE/CuO-NPs/HMIPF6 in serum and urine samples.

A novel electrochemical epinine sensor using amplified CuO nanoparticles and a n-hexyl-3-methylimidazolium hexafluorophosphate electrode

In this study, a simple and rapid analytical method development for ascorbic acid (AA) determination in food samples by using differential pulse voltammetry (DPV) method on ZnO/CNTs nanocomposite ionic liquid modified carbon paste electrode. For this, several parameters, such as ZnO/CNTs nanocomposite, ionic liquid ratio, and pH, have been studied. The cyclic voltammogram showed an irreversible oxidation peak at 0.61 V (vs. Ag/AgClsat), which corresponded to the oxidation of AA. Compared to common carbon paste electrode, the electrochemical response was greatly improved. Under the optimized conditions, the oxidation peak current of AA showed linear dynamic range 0.1–450 μmol l−1 with a detection limit of 0.07 μmol l−1, using the DPV method. The proposed sensor was successfully applied to the determination of AA in fresh vegetable juice, fruit juices and food supplement samples without previous preparation and was compared with a published electrochemical method.

Application of ZnO/CNTs Nanocomposite Ionic Liquid Paste Electrode as a Sensitive Voltammetric Sensor for Determination of Ascorbic Acid in Food Samples

This work demonstrates the fabrication of a carbon paste electrode containing NiO/CNTs modified with 1-methyl-3-butylimidazolium bromide as the binder (CPE/1-M-3BIBr/NiO/CNTs), and its applications related to the highly sensitive detection of carmoisine. The CPE/1-M-3BIBr/NiO/CNTs system was successfully utilized for the nanomolar determination of carmoisine at pH = 7.0. The CPE/1-M-3BIBr/NiO/CNTs successfully resolved the oxidation signals of carmoisine and tartrazine with a peak separation of 450 mV. This is the first time that an application of an electrochemical sensor for the simultaneous determination of carmoisine and tartrazine, two important azo dyes, has been reported. In addition, wide dynamic linear concentration ranges (70–650 μM for carmoisine and 0.1–750 μM for tartrazine), low detection limits (20 nM for carmoisine and 0.06 μM tartrazine) and excellent reproducibility were reported. The CPE/1-M-3BIBr/NiO/CNTs were successfully used for the analysis of carmoisine and tartrazine in dried fruit and soft drink samples.

An electrochemical-amplified-platform based on the nanostructure voltammetric sensor for the determination of carmoisine in the presence of tartrazine in dried fruit and soft drink samples

Three-dimensional porous reduced graphene oxide decorated with carbon quantum dots and platinum nanoparticles for highly selective determination of azo dye compound tartrazine.

A carbon paste electrode modified with 1-methyl-3-butylimidazolium bromide and CuO decorated single-wall carbon nanotubes (1-M-3-BIBr/CuO/SWCNTs/CPE) was utilized for nanomolar determination of amaranth in the presence of nitrite using square wave voltammetric (SWV) method. The structure of CuO/SWCNTs was investigated by SEM method. 1-M-3-BIBr/CuO/SWCNTs/CPE exhibited an enhancement in electro-oxidation current and active surface area. Also, 1-M-3-BIBr/CuO/SWCNTs/CPE exhibited indicated high catalytic activity toward the electro-oxidation of amaranth and simultaneous determination of it in the presence of nitrite. The 1-M-3-BIBr/CuO/SWCNTs/CPE achieved dynamic ranges 0.004–750 μM and 1.0–10,000 μM between the oxidation currents and the concentration of amaranth and nitrite, respectively. We obtained the detection limit of 1.0 nM and 0.5 μM for amaranth and nitrite, respectively. The 1-M-3-BIBr/CuO/SWCNTs/CPE was successfully applied to analysis of amaranth and nitrite in foodstuffs.

Simultaneous Determination of Amaranth and Nitrite in Foodstuffs via Electrochemical Sensor Based on Carbon Paste Electrode Modified with CuO/SWCNTs and Room Temperature Ionic Liquid

The electrochemical oxidation of bisphenol A has been studied by CdO nanoparticle ionic liquid carbon paste electrode. Cyclic voltammetry, square wave voltammetry, and chronoamperometry were used to investigate the suitability of new sensor for the electrooxidation of bisphenol A in aqueous solution. The electrooxidation of bisphenol A occurs at a potential about 50 mV less positive than with the unmodified carbon paste electrode at pH 7.0. The square wave voltammetry (SWV) peak currents of the electrode increased linearly with the corresponding bisphenol A concentration in the range of 0.3–650 μM with a detection limit of 0.1 μM. The influence of pH value and potential interfering substances on the determination of bisphenol A were studied. Finally, the proposed novel sensor was also examined as a sensitive, high selective, simple, and precise electrochemical sensor for the determination of bisphenol A in food samples.

Majede Bijad

Papers

Application of ZnO/CNTs Nanocomposite Ionic Liquid Paste Electrode as a Sensitive Voltammetric Sensor for Determination of Ascorbic Acid in Food Samples

An electrochemical-amplified-platform based on the nanostructure voltammetric sensor for the determination of carmoisine in the presence of tartrazine in dried fruit and soft drink samples

Three-dimensional porous reduced graphene oxide decorated with carbon quantum dots and platinum nanoparticles for highly selective determination of azo dye compound tartrazine.

Simultaneous Determination of Amaranth and Nitrite in Foodstuffs via Electrochemical Sensor Based on Carbon Paste Electrode Modified with CuO/SWCNTs and Room Temperature Ionic Liquid

Bisphenol A Analysis in Food Samples Using Modified Nanostructure Carbon Paste Electrode as a Sensor